OpenSTAManager is an open source management software for technical assistance and invoicing. In 2.9.8 and earlier, an authenticated SQL injection vulnerability in OpenSTAManager's Scadenzario (Payment Schedule) print template allows any authenticated user to extract sensitive data from the database, including admin credentials, customer information, and financial records. The vulnerability exists in templates/scadenzario/init.php, where the id_anagrafica parameter is directly concatenated into an SQL query without proper sanitization. The vulnerability enables complete database read access through error-based SQL injection techniques.